As is well known to those versed in the field of fire alarms, in most buildings of commercial or multiple unit character there are a plurality of fire or elevated temperature detectors or sensors, which are usually all connected to an alarm and/or annunciator means announcing the floor location of the activated detector. In the event of fire this is usually a satisfactory mode of indicating the fire location. However, there is currently a problem of false alarms insidiously caused by holding a lighted match proximate to a fire detector to activate the internal bimetal element and operate the central alarm. Upon removal of the match, the bimetal returns to its normal position and offers no indication of having been activated. Thus, the temporarily activated bimetal element close a switch to operate the annunciator, and upon answering the alarm there is found no fire, and no indication of which detector has been activated, giving rise to the conclusion that a short circuit exists and energized the alarm. In most buildings, the annunciator only indicates the floor, so that a false alarm would require testing of all the detectors on the indicated floor as well as the circuitry and wiring associated with the indicated floor.